Agent fob reducing the subface



Patented July 30,1946

AGENT FOR REDUCING THE SURFACE TENSION OF LIQUIDS Lee Leiserson,Rochester, N. Y., assignor to Virginia Smelting Company, West Norfolk,Va., a.

corporation of Maine Application April 28,1943, Serial No. 484,923

8 Claims. 1

My invention relates to agents for reducing the surface tension ofliquids and mor especially to the use of these compounds as lifting anddispersing agents to assist other surface active agents, such as wettingagents, detergents and other substances which promote wetting,penetration, swelling, frothing, and dispersing of materials b asolvent.

An object of my invention is the production of superior materials foreffecting such changes by combining these assistants with other surfaceactive materials. It has been found that the effect of such combinationsis more than additive and substantially increase the wetting,penetrating, swelling, frothing and dispersing action of the solution,and otherwise improve th action of the materials with which they areassociated.

The action of a wetting agent or any surface active compound isprimarily due to adsorption. If a textile is immersed in a solution withwetting properties, the adsorbed air film on the surface isfirstdisplaced, due to the selective adsorption of wetting agentmolecules. Wetting agents, and lifting agents, both reduce the surfacetension of aqueous solutions. They do this because they have a limitedsolubility in water. The molecules of the surface active compound areliterally squeezed out from the interior of the liquid to the surface.The effectiveness of a particular compound in reducing the surfacetension depends on the orientation of the molecules at the interface,liquid-air, and the disrupting efiect this orientation has on the forcesbetween the water molecules at the interface. The best materialseffectively reduce the surface tension of water to that of ahydrocarbon. The reduction of surface tension means that the liquidspreads easily and quickly over a large surface. Thus,

when a fiber is immersed in a wetting agent solution, the air, then oilor wax, is displaced from the fiber due to the selective adsorption ofthe wetting agent molecules. The solution spreads quickly over the largesurface of the fiber and the wetting agent acts as a bond between twosubstances that might not otherwise adhere to each other.

The action of a lifting agent, which is generally used in lowconcentrations where it would have little or no effect if used alone, isto introduce into the wetting agent solution another substance that willbe preferentially adsorbed. It thus prolongs the time a solution may beused before exhaustion of the wetting agent. The

lifting agent has a solvent action for oils and waxes and facilitatestheir removal from the fiber,

where a. fiber is acted upon. As some of the lifting agent remains onthe fiber after removal from the solution, it promotes rewetting onimmersion in water and promotes ease of handling in subsequent textileoperations. In dyeing, the lifting agent has a great importance. Itfacilitates the dispersion of clumps and aggregates of color particles.It insures better solubility and the result obtained is better and ofmore even color.

Ketones can effect lowering of surface tension but when they arecombined with efficient wetting agents and operate as lifting agents themixture not only is more specific and effective than would be expected,but the lifting agent has a solvent action, as above explained, whichmakes it an excellent leveling agent for dye baths, and as above setforth, assists by remaining to some extent with the fiber in the futurehandling of the materials.

The lifting agents greatly increase the effectiveness of wetting agents,and other surface active compounds in many fields of use, such as thepetroleum industry, metal processing, the paint industry, cleaners andcleaning compounds, the rubber industry, agriculture and cosmetics,textiles both natural and synthetic, to giv but a few fields of use.

The single sheet of drawings-is a table showing the increased efliclencyof one wetting agent when mixed with the lifting agents.

A principal feature of the present invention resides in the discoverythat ketones having 5 to 12 carbon atoms can be used effectively asassistants in conjunction with other materialswith surface activeproperties, such as sodium alkyl sulfates, sodium oleate, sodium alkylnaphthalene sulfonates, etc. To show the importance of these ketones asassistants or lifting agents when used with other materials havingsurface active properties, below is given a procedure for a canvas discwetting test, which procedure has been employed with a number of.combinations of various ketones operating as lifting agents in admixturewith certain agents for reducing the surface tension of liquids. Thedata given hereinafter show the remarkable results obtained by the useof these lifting agents in combination with these surface activematerials.

Canvas disc wetting tests are employed to compare the wetting ability ofvarious wetting materials. The following test was reported by Seyferthand Morgan in the American Dyestufl. Reporter, 2'7, 525 (1938) and inChemical Abstracts 32, 8789 938).

The tests consists of measuring the sinking time of a 1" diameter,number 6 canvas disc in a known solution. Conditions of temperature,concentration of wetting agent, water hardness and pH are controlled.The canvas used in these tests was natural color and "unwaterprooted.All tests were made with discs cut from the same strip of cloth, toeliminate variations due to the canvas.

The solutions for the tests were made from -a stock 1% solution. Allwere madewith distilledwater. The proper ampunt oi. concentratedsolution was measured into a 500 cc. volumetric flask. An organicsolvent, ii any. was measured out and added. The mixturewas then dilutedwith distilled water to 500 cc. This amount, of the solution tobe testedwas placed-in a 600 cc.

Example 4 Methyl n-amyl ketone as a lifting agent Sodium ditertiarybutyl naphthalene sultonate as a wetting agent V. Example 5 Isophoroneas a lifting agent--.

cc. per liter- 0.8

g. per liter 0.3

' cc. per 1it er 03 Sodium ditertiary butyl naphthalene sulionate'as awetting agent g. per Men. 0.3

Y I Eaample 6 Methyl n-butyl ketone asa litting agent cc. per liter- 0.8

I Sdium ditertiary butyl naphbeaker. A Gooch funnel 1%" in diameter andhaving a barrel 3" long is inverted in the solution and the whole'isbrought to the desired temperature, usually degrees C. Working rapidlythe Gooch funnel is removed, a canvas disc placed in the tunnel whichthen is again inserted into the solution; at the same time a stop watchis started. The time-recordedis that interval required for the disc .tosink to touch the bottom of the beaker. After stirringthe solution thetest may be repeated for cheeke'on the sinking time. To get consistentresults it is'necessary to insert the disc so that when it wets.

one bubble of, air comes oil at a time-from the same position near theedge of the disc The data may beplotted on logarithmic paper;

points, when connected, give a straight line.

Seyferth and Morgan-report the deviation from mean wetting time to be9.4% v

The tests which are reported hereinafter were conducted by the procedureJust above outlined. The table in Figure 1 shows the results of theSeyferth and Morgan canvas disc wetting test on solutions containingketoneg as lilting agents, to-

gether with a wetting agent. All solutions contained 0.3 gram per literof sodium ditertiary butyl naphthalene sulfonate, as the wetting agent,made from an allryl naphthalene fraction that had a boiling point of185-195 C. at 5 mm.

The concentration or the ketone lifting agent wa is no case large enoughby itself to cause sinking the canvas disc in less than a matter orhours. The wetting agent was sufllciently concentrated to cause sinkingof the disc in an average oi about 63 seconds. ,The temperature ofalisolutions during the test was 25 C.

v Example Camphor as a lifting agent.-- g. per liter-..

Sodium ditertiary butyl naphthalene sulionate as a wetmg agent g.perliteh- 0.3

' Example 2 v 'Diisobutyi ketone as a lifting agent (cloudy sat.solution) cc. per liter- 0.8 Sodium ditertiary butyl naphthalenesulfonate a a wetting agent g. per liter... 0.3

I Eaample 3 1,1,3 trimethylcyclohexanone- 5 as a lifting agent cc. perliter- 0.8 Sodium ditertiary butyl naphthalene sulfonate as a wettingagent 0.3

8. W1 liter" thalene suli'onate as a wetting agent g. per men. 0.3

Example 7 Cyclohexanoneas. a lilting agent. cc. per liter- 0.8 Sodiumditertiary butyl naphthalene sulfonate as a wetting agent g. per Men.0.3

I Other examples of combinations which I have found to possess excellentproperties are as fol- The use of alcohol-is optional. but when added,thepurpose is to produce a homogeneous mixture 01f the eamphorand thewetting agent.

Example 1 1 7 Sodium ditertiary butyl naphthalene sulfonate- 4 parts 1g. per liter Isophorone 6 parts or less Example 12 Sodium ditertiarybutyl naphthalene sulfonate- 6 parts l g. per liter Methyl pr0py1ket0ne4 parts or less Example 13 Sodium ditertiary butyl naphthalene sultonatefrom a fraction boiling at 250 C. at 20 mm. and camphor in the ratio of10:1...

- Ekrample 14 40% sodium ditertiary butyl naphthalene sulfonate from afraction boiling at 190 250' C. at 20 mm. in methyl n-amyl ketone cc.per liter 1.25

g. per Men. 0.66

Example 15 50% sodium oleate in methyln-amyl ketone Example 16 cc. perliter- 1.38

The addition of the ketone from 5-12 carbon atoms to any surface activesubstance has an effect on the activity of the latter which isconsiderably greater than that which would normally be exerted bycalculation from the surface activity of the separate components. Thesolutions of the mixture havean increased activity as regards wetting,penetrating, detergent, frothing and dispersing action. As specificexamples which do not limit the scope of my invention, the surfaceactive material may differ as widely as soaps, sodium alkyl naphthalenesulfonates, and sodium alkyl sulfates.

Other combinations which come within the scope of this invention are thecombination of my lifting agents with normal n-amyl ketone and sodiumdi-amyl naphthalene sulfonate.

Saturated Water solutions of ketones may also be used alone for wettingpurposes, and in this use they may be employed not as lifting agents incombination with a wetting agent, but as the principal surface activeagent. The preferred material for such purposes is a ketone having from5-12 carbon atoms, in the form of saturated water solutions.

I claim:

1. A liquid, the surface activity of which has been changed, comprisinga solution of an alkyl naphthalene sulfonate and a saturated aliphaticketone selected from the group consisting of methyl-n-amyl ketone,diisobutyl ketone and methyl-n-butyl ketone.

2. A liquid, the surface activity of which has been changed, comprisinga solution of a sodium alkyl naphthalene sulfonate and a saturatedaliphatic ketone selected from the group consisting of methyl-n-amylketone, diisobutyl ketone and methyl-n-butyl ketone.

3. Aliquid, the surface activity of which has been changed, comprising asolution of an alkyl naphthalene sulfonate and methyl-n-amyl ketone.

4. A liquid, the surface activity of whichhas been changed, comprising asolution of an alkyl naphthalene sulfonate and diisobutyl ketone;

5. A liquid, the surface activity of which has been changed, comprisinga solution of an alkyl naphthalene sulfonate and methyl-n-butyl ketone.

6. A liquid, the surface activity of which has been changed, comprisinga solution of a sodium alkyl naphthalene sulfonate and methyl-n-amylketone.

'7. A liquid, the surface activity of which has been changed, comprisinga solution of a sodium alkyl naphthalene sulfonate and diisobutylketone.

8. A liquid, the surface activity of which has been changed, comprisinga solution of a sodium alkyl naphthalene sulfonate and methyl-n-butylketone.

LEE LEISERSON.

